HANDOFF.md: note stepper hover + vertical-slider UX tweak on Phase 17

Annotates Phase 17 in §9 Shipped with UX tweak `c07af1c` and a short
summary of the change — popover is now hover-to-open (pointerover /
pointerout with 200 ms grace) instead of click-to-open, and the
optional range slider renders vertically (writing-mode vertical-lr +
direction rtl with slider-vertical / orient="vertical" fallbacks).
Focus and pointerdown triggers still present for keyboard and touch
users. SHA appended to §13 git history.

No code changes.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

HANDOFF.md

@@ -422,7 +422,7 @@ with a `BOOTSTRAP_ADMIN` audit row.
       localStorage denial fallback).
 
 - [x] **Phase 17 — Hide native number spinners + custom 0.5-step
-      stepper popover** (`b457896`). Three classes of number input —
+      stepper popover** (`b457896`, UX tweak `c07af1c`). Three classes of number input —
       day cells, RTB cells, task assignment cells — deal in half-day
       increments (or 0.05 for RTB). Browsers rendered each as
       `<input type="number">` with tiny native up/down spinner
@@ -481,7 +481,14 @@ with a `BOOTSTRAP_ADMIN` audit row.
       input, day-cell stepper at 0.5 step, RTB stepper at 0.05
       step, task-assignment stepper on both show and present views
       with no range slider because no max, Escape + outside-click +
-      dark-mode polish).
+      dark-mode polish). **UX tweak `c07af1c`**: the popover is
+      now hover-to-open (pointerover / pointerout with a 200 ms
+      grace timer so transit between input and popover is safe)
+      instead of click-to-open, and the optional range slider
+      renders vertically (writing-mode: vertical-lr + direction:
+      rtl, with slider-vertical / orient="vertical" fallbacks).
+      Focus and pointerdown triggers remain for keyboard and
+      touch users respectively.
 
 ### Upcoming
 
@@ -565,6 +572,8 @@ before acting — nothing here is load-bearing once it grows stale.
 ## 13. Git history (as of this handoff)
 
 ```
+c07af1c Stepper popover: hover-to-open + vertical range slider
+735aa4f HANDOFF.md: mark Phase 17 shipped
 b457896 Phase 17: hide native number spinners + custom 0.5-step stepper popover
 712bcc5 HANDOFF.md: add Phase 17 plan (number-stepper popover + hide native spinners)
 0d738b2 HANDOFF.md: mark Phase 16 shipped